Partners at national firms Pinsents and Masons this week voted in favour of a merger, creating a 240-partner giant to be known as Pinsent Masons in December.


The top-15 national law firm, with a predicted combined turnover of £150 million, will be headed by Pinsents' senior partner Julian Tonks.


Masons partners voted unanimously in favour, while Pinsents obtained the 75% of votes needed for the deal to go ahead.


Pinsents managing partner David Ryan will take over the management of the merged firm, with Masons' senior partner Martin Harman taking on the ambassadorial role of chairman. He will also chair the firm's non-executive council.


Pinsent Masons' executive board will comprise the firm's senior and managing partners, plus Masons partners Tony Bunch and Alastair Morrison, and Pinsents' finance director Stephen Hancock.


Pinsents and Masons both have offices in London, Leeds and Manchester. Pinsents also has its head office in Birmingham, while Masons also has offices in Bristol, Edinburgh and Glasgow. Masons is expected to move into Pinsents' office in Leeds once the merger is completed, while the new firm will continue to run two offices in Manchester and London for the time being. There are no planned redundancies for legal staff.


Mr Harman said: 'This merger will enable us to offer a wider service to our technology, projects and construction clients, by combining the corporate, finance and property strengths of Pinsents. There are no areas where we directly compete, and conflicts are very modest. Our corporate practice is much smaller than Pinsents' and had not been able to grow organically quickly enough to offer a full service in our chosen markets.'


Pinsents has more than 150 partners at present, while Masons has just fewer than 100.